This invention relates to the inspection of a face of a tube, and more particularly, to an automatic tube processing system and method for preparing and inspecting the face of a tube, for use in nuclear fuel assemblies, during the manufacture of the tube.
Several procedures are performed during the manufacturing process of a tube, such as cutting the tube to a desired length, finishing the face of the tube, and inspecting the face of the tube for defects, such as scratches, chatter, steps, nicks, burrs, and out of squareness.
Tubes may be utilized for various uses and in various applications, such as in nuclear fuel assemblies. U.S. Pat. No. 3,791,466, issued Feb. 12, 1974 to Patterson et al., describes several types of thin walled tubing used in nuclear fuel assemblies, such as the nuclear fuel tube within which nuclear fuel pellets are housed during operation of the nuclear reactor, the guide thimble tube which provides structure to the nuclear fuel assemblies and houses the control rods within the nuclear reactor, the instrumentation tube which contains various instruments housed within the nuclear reactor, and the tube for containing an internal burnable absorber rod which regulates the power within the nuclear reactor core.
Currently, during the manufacturing process of a tube, the tube is advanced by an advancing mechanism to a rotatable collet, which grips and rotates the tube. A motor is connected to the collet to provide the rotation for the collet. When a solenoid is activated, a movable stop extends from the solenoid to a predetermined distance, pushing the tube through the collet to a desired position. The collet grips the tube, while rotating, in this position. A cutting bit advances toward the tube and cuts the tube to a desired length. The cutting bit may also make a second cut to perform the finishing process on the face of the tube.
After the cutting and finishing processes, the tube is inspected for defects on the face of the tube. One approach to inspecting the face of the tube is for an individual to shine a flashlight onto the face of the tube in a circular manner to visually inspect the tube face. However, because this approach is performed manually, it is time consuming.
Another approach to inspecting the face of the tube is for an individual to visually check the surface of the face of the tube with a magnifying glass. Also, the individual may use a plug gauge to check for burrs on the inside diameter of the tube and may use a dial indicator to check for out of squareness on the face of the tube. However, because these approaches do not provide a complete inspection of the face of the tube, an additional inspection step, such as the above mentioned approach, is also used in the inspection process.
Currently, approximately 1 out of 15 tubes may be preliminarily inspected with a plug gauge, a dial indicator, and a magnifying glass by an individual. If the tube passes this preliminary inspection, then the tube is moved to a different location within the manufacturing facility for the next stage of the manufacturing process of the tube. After the manufacturing process is complete and the tube is ready for shipment, the final inspection is performed. At this final inspection stage, every tube is visually inspected by an individual shining a flashlight onto the face of the tube in a circular manner and by using a plug gauge and dial indicator. If a defect, such as a scratch, chatter, step, nick, burr or out of squareness is discovered on the face of the tube, then the tube will have to be reworked, requiring removal of the tube from this location in the manufacturing facility to the location in the facility for performing the cutting and finishing processes. Because only 1 out of 15 tubes may be preliminarily inspected at the finishing stage, possibly a defect may be discovered upon final inspection on the face of any of the tubes that were not preliminarily inspected at the finishing stage. Also, if a tool used in the manufacturing process was damaged, the tool may have caused defects in a number of tubes, requiring a large number of tubes to be reworked.
Therefore, the disadvantages to the above mentioned approaches are that to perform these inspections on every tube visually and manually by an individual at the time of finishing the face of the tube while the tube remains positioned at the finishing stage is time consuming. To selectively inspect a percentage of the tubes, such as 1 out of 15 tubes, at the finishing stage of manufacture creates the possibility of defective tubes being processed through the manufacturing operation until the defects are discovered at the final inspection. To perform the inspection of every tube at the final stage of manufacturing is also time consuming because if a defect is discovered on the face of the tube, the tube must be transported from the final inspection location to the cutting location within the facility and must be reworked from the cutting stage through to the final inspection until the defects no longer exist.
Therefore, what is needed is an apparatus and method that automatically inspects the face of a tube efficiently and economically, while the tube is still in the manufacturing process, preferably while positioned at the finishing stage of manufacture, to increase productivity.